It’s been a while since I’ve updated this blog. The combination of fieldwork, teaching, and just being generally busy, hasn’t provided much time for extra-curricular writing.
I’m taking a bit of a departure from previous posts, and just providing an update post of some recent papers and research coming out of my research group. When I get some more time I’ll update the blog with some more paper reviews, and I’m always interested in comments and suggestions from people.
My group has been working on a variety of projects, including massive sulphide research in Newfoundland (and elsewhere), work on portable X-ray fluorescence, and general work on quality control and quality assurance in lithogeochemical data.
My MSc student Shannon Gill has just published her first fieldwork article in Geological Survey of Canada (GSC) Current Research. Her research is on mineralogy, metal zoning, and evolution of the Zn-Pb-Ba-Ag-Au-bearing Lemarchant volcanogenic massive sulphide deposit. The paper breaks out the various facies and illustrates how the deposit is different than most bimodal felsic VMS deposits in having abundant sulphosalts and a likely epithermal input to the metal budget of the deposit. The paper can be downloaded here.
My PhD student Jean-Luc Pilote has just published his first fieldwork article of his PhD also in GSC Current Research. His thesis is aimed at reconstructing the stratigraphy, structure, and hydrothermal alteration of the Au-bearing Ming VMS deposit. His work is also utilizing lithogeochemistry, U-Pb geochronology, and radiogenic isotopes to understand the petrology, chemostratigraphy, alteration and timing of various events in the deposit, and the evolution of the deposit to the regional tectonic and metallogenic framework of the Baie Verte Peninsula. The initial results of his mapping last year on the 1807 Zone of the Ming Deposit are presented here.
In addition to students, I have has two papres recently published. The first paper is an invited contribution to Geoscience Canada and is a review article on quality assurance and quality control (QA/QC) in lithogeochemistry. The paper is written for a non-expert and covers various topics including sampling, precision, accuracy, contamination, and general monitoring of lithogeochemical data during a QA/QC program. For those interested in this you can get a copy of the paper here.
The second paper that has come out is on the utilization of portable X-ray fluorescence and published in Geochemistry: Exploration, Environment, Analysis. My group has been spending a lot of time developing pXRF for utilization in lithogeochemistry and this paper reports on our approach to calibrating the instrument (single point calibration method) and provides results on international reference materials and samples that had previously been analyzed by other methods. The results illustrate that the pXRF has considerable potential as an initial means of screening data and providing ‘fit for purpose’ information, but it is not a substitute for traditional methods. The other major outcome of this paper is that it provides a calibration method that is relatively straightforward, and yields reasonably precise and accurate data to understand alteration, chemostratigraphy, and general metal values for samples. The approach is now being used in conjunction with collaborators on archived assay pulps from other sites/deposits for alteration mapping and chemostratigraphy. Those interested in a copy of the paper can find it here. There are also numerous other great papers recently published in a thematic set on pXRF in Geochemistry: Exploration, Environment, and Analysis. This group of papers is worth checking out as it is the current state of pXRF knowledge applied to lithogeochemistry and exploration geochemistry.
Stay tuned as well as there some more papers coming out of our group in the coming months on gold-rich massive sulphide deposits and emplacement mechanisms in VMS deposits. I’ll also do a quick overview of these papers when they come out.
Economic Geology Blog 